Interstage explosively operated hy-



March 17, 1964 E. J. MURPHY 3,125,103

INTERSTAGE EXPLOSIVELY OPERATED HYDRAULIC LINE SEPARATION DEVICE Filed Jan. 13, 1961 FIG. 3 I

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EMM T J. MURPHY w ATTORNEY United States Patent 3,125,108 INTERSTAGE EXPLOSIVELY OPERATED HY- DRAULIC LINE SEPARATION DEVICE Emmet J. Murphy, Redwood City, Calif., assignor to General Precision, Inc., a corporation of Delaware Filed Jan. 13, 1961, Ser. No. 82,490 1 Claim. (Cl. 137-68) This invention relates to a tubing cutter and sealing device and more particularly to an interstage hydraulic line separation device which may be activated by an explosive initiator to pinch off the tubing thus sealing the hydraulic supply prior to shearing the line and disconnecting a portion of the hydraulic system.

Many other devices have been produced for cutting tubing in various different ways. However, none of these devices have been adapted to instantaneous sealing and cutting of hydraulic lines under pressure and particularly with the reliability required during the separation of the stages of a missile in conjunction with other separating devices which must be actuated simultaneously and without failure.

Briefly stated, one preferred embodiment of the interstage hydraulic line separation device of the present invention consists essentially of a cylindrical body having a ram mounted for axial movement therein by an explosive initiator mounted in one end of the body adjacent the ram. A section of tubing extends transversely through the body with a coupling on each end. Firing of the initiator drives the ram down pinching or crushing the ductile tubing between a curved portion of the ram and the body. The crushing action of the ram seals one end of the tubing and maintains the hydraulic supply pressure in the stage which is still continuing to function. Continued ram motion shears the tubing at the other end, and a free disconnect sleeve in the body surrounding this end of the tubing permits this portion which is connected to the stage being separated to be readily released.

One object of the present invention is to provide an interstage hydraulic line separation device which may be rapidly and reliably actuated to shear and seal the hydraulic lines between stages of a missile which are being separated.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is an elevational view illustrating one preferred embodiment of the present invention;

FIG. 2 is a sectional View taken on the center line of the device of FIG. 1;

FIG. 3 is a sectional View taken on the line 3-3 of FIG. 2;

FIG. 4 is a sectional view similar to FIG. 2 but showing the ram and tubing after the cutting and sealing operation; and

FIG. 5 is a detailed sectional view on an enlarged scale illustrating one preferred form of explosive initiator.

Referring now to the drawings in detail, the interstage hydraulic line separation device of the present invention is preferably formed with a heavy walled cylindrical body 11 which has a threaded plug 12 inserted in one end thereof and a threaded bushing 13 inserted in the opposite 3,125,108 Patented ,Mar. 17., 1964 2 end thereof. The bushing 13 receives a threaded initiator 14 having a threaded connector 15 integrally formed thereon.

A short section of ductile tubing 16 extends transversely through the body 11 and is provided with a coupling at each end for connection to the hydraulic system in the two stages of the missile. The coupling 17 is adapted to be connected to the hydraulic system of the stage being separated and the tubing 16 adjacent this end is surrounded by a disconnect sleeve 19. The coupling 18 is adapted to be connected to the hydraulic system in the stage which continues to function and where the supply pressure must be maintained.

Referring now more particularly to the sectional views of FIGS. 2 through 5, ram 21 is cylindrical in cross section and is provided with a keyway 22 to receive a key 23 secured in bore 24 for orientation and guidance of the ram 21 in the bore 24 of the body 11.

The ram 21 as shown in FIG. 2 is provided with a depending curved portion 25 which bends and crushes the ductile tubing 16 around the rounded corner 26 to pinch off and seal the tubing 16 adjacent the coupling 18. A recess 46 is provided on the ram, as shown in FIGURE 4, for the purpose of pinching the hydraulic line 16 between the side of the ram 21 and the wall 11 of the cylinder in the area adjacent the rounded corner 26 and the bottom closure 12.

The other side of the ram 21 is provided with a sharp cutting portion 27 which cuts through the tubing 16 adjacent the free disconnect sleeve 19 for completely severing or shearing the tubing after it has been pinched 011 and sealed by the curved portion 25.

It will be apparent that the coupling 17 and the free end of the tubing 16 adjacent thereto will be readily pulled free since the free disconnect sleeve 19 will pull out of the opening in the body 11 regardless of whether or not the tubing 16 may have been swaged over.

The ram 21 may be actuated by any desired means, but is preferably driven by an explosive initiator 14 which has an exploding bridgewire 31 connected by leads 32 and 33 extending through an insulating plug 34 to suitable circuitry (not shown).

The bridgewire 31 detonates an explosive composition 35 which will blow out the thin wall 36 and drive the ram 21 at extremely high speed to pinch off and sever the tubing 16.

Obviously, many other modifications and variations of the present invention may be made within the scope of the following claim.

What is claimed is:

A hydraulic line sealing and cutting device comprising:

(A) a cylinder having a first and second coaxial transverse opening extending through the walls thereof and disposed intermediate the ends and in open communication with the hollow portion of said cylinder, the first of said openings being adapted to receive a hydraulic line,

(B) a sleeve loosely mounted in the second of said openings, the inside diameter of said sleeve being the same as the inside diameter of said first coaxial transverse opening,

(C) a first and a second closure means for respectively sealing the upper and lower ends of said cylinder,

(D) a ram slidably mounted within said cylinder and 3 normally positioned adjacent said first closure means, said ram having:

(a) a head portion and a depending portion thereon, the overall length of said ram being no greater than the distance between the inside surface of said first closure means and the side of said first opening adjacent said upper closure,

(b) a cutting edge thereon adapted to sever said hydraulic line and positioned adjacent said sleeve between the head portion of said ram and the lower extremity of said depending portion,

(0) a recess thereon positioned adjacent said first transverse opening for coaction with the inner 4 wall of said cylinder between said first opening and said second closure, whereby said hydraulic line is pinched therebetween, (E) ram actuating means, and (F) said second closure means being positioned to coact with the lower extremity of said depending portion to close said tube when said ram is actuated.

References Cited in the file of this patent UNITED STATES PATENTS 426,677 Owens Apr. 29, 1890 2,937,654 Wilner May 24, 1960 3,011,750 Johnson et al Dec. 5, 1961 

